Standart form is
ax + by = c
In our case
y = x + 48
y - x = 48
The point-slope form is
(y - yo) = m.(x - xo)
Since we know that
y = x + 48
Let's make some changes:
(y - 0) = m.(x + 48)
(y - 0) = 1.(x + 48)
So, our slope is m = 1, and we have a point (-48, 0)
